By using high purity aluminum powders and multi-walled carbon nanotubes (MWCNTs) as raw materials, MWCNTs/Al composites were fabricated with ball milling, followed by cold pressing, vacuum sintering, and hot extrusion. It was found that when the sintering temperature was 863 K, MWCNTs/Al composite sintered for 4 h showed good comprehensive properties, and its tensile strength and elongation reached to 156 MPa and 21%, respectively. The comprehensive mechanical properties of the composites became better with raising sintering temperature when the sintering time was 4 h. When the sintering temperature raised to 923 K, the tensile strength of the composite reached to 167 MPa which is three times more than that of annealed high purity aluminum, mainly due to the higher density and better interface bonding resulted from higher sintering temperature. CNTs' pulling out were observed obviously in the fractured surfaces, and load transfer may be the main strengthening mechanism.

A series of Ni0.5Zn0.5Fe2O4 (NZO)/polyvinylidene fluoride (PVDF) composites were prepared and studied for their potential application as magneto-dielectric antenna substrate materials. The NZO ferrite powders were synthesized by the solid-state reaction method and then annealed at different temperatures of 700, 900 and 1100 °C. The influence of the annealing treatment on the grain size, crystallinity and magneto-dielectric properties were discussed. The magnetic and dielectric properties of the composites were measured in 1 MHz–1 GHz and 100 Hz–1 GHz, respectively. With the annealing temperature increase from 700 to 1100 °C, the initial permeability of the composites increases from 3.89 to 7.93, while the static permittivity changed regularly with the growing grain size. Almost equal values of μ′ and ε′ are obtained in the composite sample with the 1100 °C annealed NZO powders. Considering the relatively low magnetic and dielectric loss tangent, this material is the promising candidate for the design of miniaturized antennas.

Single- and double-hit hot compression tests were performed at 1030 °C and strain rate of 0.1 s−1 on Ti–13V–11Cr–3Al beta Ti alloy to investigate the flow behavior and mechanism of microstructural evolution during the interpass period. It was observed that the flow stress level and the extent of yield point phenomena (YPP) were increased by an increase in the grain size. After the first pass, the microstructure was bimodal of large deformed grains and small recrystallized grains formed by continuous dynamic recrystallization. The increase in the interpass time to 100 s, led to the decrease in the yield drop and extent of YPP. However, the further increase in the interpass time to 300 s would result in an inverse effect. A combination between static recrystallization and metadynamic recrystallization was found responsible for grain refinement in the samples subjected to the interpass times below 100 s. At longer interpass times, i.e., 300 s, grain growth increased the average grain size.

In this study, a mesoscale dislocation simulation method was developed to study the orthogonal cutting of titanium alloy. The evolution of surface grain structure and its effects on the surface mechanical properties were studied by using two-dimensional climb assisted dislocation dynamics technology. The motions of edge dislocations such as dislocation nucleation, junction, interaction with obstacles, and grain boundaries, and annihilation were tracked. The results indicated that the machined surface has a microstructure composed of refined grains. The fine-grains bring appreciable scale effect and a mass of dislocations are piled up in the grain boundaries and persistent slip bands. In particular, dislocation climb can induce a perfect softening effect, but this effect is significantly weakened when grain size is less than 1.65 μm. In addition, a Hall–Petch type relation was predicted according to the arrangement of grain, the range of grain sizes and the distribution of dislocations.

Three dimensional (3D) porous graphene decorated with MoO2 nanoparticles were successfully synthesized by hydrothermal method and characterized by SEM and TEM, x-ray diffraction, Raman spectra, x-ray photoelectron spectroscopy, nitrogen adsorption–desorption analysis and electrochemical experiments. The results revealed that the in situ formed monoclinic MoO2 nanoparticles were randomly decorated on the surface of graphene sheets and the obtained graphene–MoO2 nanohybrids were 3D porous structures. The mass ratio of molybdenum precursor with GO has effects on the specific surface area and the electrochemical properties of the nanocomposite. The M30G1 (the mass ratio of molybdenum precursor with GO was 30:1) composite electrode exhibited a higher specific capacitance and better cycling stability. The specific capacitances were 356 F/g at the current density of 0.1 A/g in KOH electrolyte, which predicted their potential application in energy storage. The electrochemical performance of M30G1 composite was also investigated in Na2SO4 electrolyte, which was poorer than that in KOH electrolyte. Therefore, the chosen of electrolyte is important to materials performance.

Four types of W-doped graphite-like carbon (W-GLC) films were deposited under different W target currents by magnetron sputtering method. The effects of W content on the microstructure and properties of the W-GLC films were analyzed via various characterization techniques. The results show that the microstructure of the W-GLC films tends to be loose, while the surface roughness distinctly increases with the increase in the W target current. Moderate W-doping can considerably improve the mechanical properties and wear resistance of the film, which will subsequently decrease as the W content becomes excessive. Moreover, the friction coefficient of the W-GLC films does not show a distinct change, but significantly increases when the W target current increases from 0.9 A to 1.2 A. In particular, when the W target current is 0.6 A, the friction coefficient and the wear rate of the W-GLC film are 0.02 and 3.8 × 10−17 m3/N·m, respectively, exhibiting excellent tribological properties.

We report the effect of patterning on photoelectrochemical (PEC) water-splitting performance. Oxide–oxide heterostructures based on horizontal and vertical heterojunctions were fabricated on transparent conductive oxide glass by sequential plasma enhanced chemical vapor deposition (PECVD) of individual metal oxide. Featured masks were employed to enable three-dimensional patternings of stripes and cross-bars structures formed by Fe2O3 and TiO2 layers. PEC measurement was carried out by a three-electrode cell. It was found that double layered TiO2//Fe2O3:FTO showed a decrease in PEC performance when compared with single Fe2O3:FTO layer, whereas triple-layered Fe2O3//TiO2//Fe2O3:FTO (both patterned and unpatterned samples) displayed enhanced photocurrent density. The results show that the existence of multiple phase boundaries does not always add up to PEC enhancement observed in single heterojunction.

A consistent description of the hydrogen permeation through metal membrane based on hydrogen chemical potential proposed has been explained in detail. The hydrogen flux is proportional to the PCT factor, f PCT, consistently, which reflects the shape of the pressure-composition-isotherm (PCT curve) of the material. In addition, in view of the PCT factor, f PCT, and the ductile-to-brittle transition hydrogen concentration, DBTC, a concept for alloy design with high hydrogen permeability and strong resistance to hydrogen embrittlement has been proposed. In this concept, it is important to design alloy composition with appropriate PCT curve under the given pressure and temperature condition. As an example, V–9 mol% Al alloy has been designed, which exhibits high hydrogen flux without brittle fracture under given condition. Thus, the new consistent description is useful not only for the understanding of the hydrogen permeation property but also for the alloy design.